This isn't a bug.

There were hundreds of posts about this last year.
This is a chipset feature. I don't remember why but it's by design.

Most boards bioses created a workaround for this; I think by managing to prevent the PSU from shutting down power to the system, while the board itself still does a "cold reset", which is transparent to the user--the power is simply not cut. For example, on asus boards, with the BIOS that prevents the "cold boot", you can STILL tell a difference between how the board POSTs at 266 FSB vs >330 FSB, including the beep and post speed (even more noticable if you have a monitor that loses the signal temporarily between boots at >330, and doesn't at 266).